5S methodology

The 5S methodology, as described in Hiroyuki Hirano s 5 Pillars of the Visual Workplace, is the foundation for making company wide improvements in both the production facility and the front office, so that the just-in-time production strategy of inventory management can be implemented. 

Another reaction that has potential is the intramolecular ene reaction, which preferentially results in five-membered rings Because fluorinated ketones have a propensity for undergoing intermolecular ene reactions [5S], this reaction has tremendous synthetic possibilities Only one example of an ene reaction of an unsaturated trifluoromethyl ketone has been reported, but it indicates the potential of the methodology [59] (equation 59)... 

An entry to. yyrt-2-methoxy-3-hydroxycarboxylic acids is also opened using similar methodology. Thus the norephedrine derived (4/ ,5S)-3-(2-methoxy-l-oxoethyl)-4-methyl-5-phenyl-1,3-oxazolidine-2-one 23105a, as well as the phenylalanine derived (4S)-4-benzyl-3-(2-methoxy-l-oxoethyl)-l,3-oxazolidin-2-one 25105b, can be added to aldehydes via the boron enolates to give, after oxidative workup, the adducts in a stereoselective manner (d.r. 96 4, main product/sum of all others). Subsequent methanolysis affords the methyl esters. 

Following an almost identical methodology, Nicolaou has synthesised the (3S, 5S, 75j-lactone 18 corresponding to the C(l)-C(10) fragment of nystatin Aj [5],... 

Self-aldolization of acetaldehyde provided one-step enantioselective syntheses of (5R)- and (5S)-Hydroxy-(2E)-hexenal using either (R) or (S)-proline as catalysts of the homologation of three acetaldehyde units ee-values of up to 90% were obtained [25]. Using this methodology, a series of triketides was prepared by slow addition of propionaldehyde into acceptor aldehyde and (S)-proline in DMF, and the isolated lactols were converted to the corresponding d-lactones [26]. The product enantiomeric purity was typically moderate because of the isomerization... 

Applications with diazo esters that undergo insertion into a C-H bond vicinal to the incipient chiral center demonstrated further advantages of this catalytic methodology for asymmetric synthesis. 2,3,4-Trimethyl-2-pentyl diazoacetate formed lactone 19 exclusively (eq 7) in 60% ee (77% isolated yield) with Rh2(5S-MEPY)4 and Rh2(5/ -MEPY)4 and in 70% ee with the neopentyl ester analog, Rh2(5S-NEPY)4 (82% isolated yield). Cumyl diazoacetate underwent insertion into the normally disfavored 1° C-H bond (eq 8) to yield lactone 20 in 76% ee (30% isolated yield) with... 

The work of Martin and co-workers [49] has shown that excellent diastereo-control can be achieved in cyclopropanation of single enantiomers of chiral secondary diazoesters by catalyst matching. Thus, while Rh2(5R-MEPY)4 and the (S)-diazoester in Eq. (27) react to afford a 37 63, endo exo mixture of diastereoi-someric cyclopropanes, the 5S-MEPY catalyst affords a >95 <5 ratio of the same products. A final illustrative example of the versatility of this methodology is shown in Eq. (28). Here diazoacetates of prochiral divinyl carbinols undergo intramolecular cyclopropanation catalysed by Rh2(5S-MEPY)4 with exceptional enantiocontrol [49]. 

SmithKline chemists adapted singlet oxygen oxidation methodology to prepare ( )-methyl (5S), (6S)-oxido-7-hydroxyheptanoate 730 (n=l), a key fragment of leukotrienes A-E (Scheme 1.201). 4,5-Diphenyl-2-methyloxazole 231a was converted to the allylic alcohol 727 in five or six straightforward steps. 

Liebscher and co-workers reported a general method of preparing optically active 2-(a-aminoalkyl)oxazoles 1167 via an asymmetric a-alkylation of 2-(ami-nomethyl)-4,5-diphenyloxazole 1164 (Scheme 1.301). Their work complements the known methodology for asymmetric a-alkylation of other aminomethyl hetero-cycles. Thus Lewis acid-catalyzed condensation of 1164 with commercially available (IS, IS, 5S)-2-hydroxypinanone generated (IS, 2S, 5S)-3-(4,5-diphenyl-oxazol-2-ylmethylimino)-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol 1165 in 65% yield. 

I can hear some who are familiar with lean groaning right now. Please, we do not want to hear any more about this simple approach, they may be thinking. Well, as with all lean tools, the concepts of 5S are indeed simple to understand. It provides a structured step-by-step methodology that will result in a clean, organized work area. A personal experience of mine may help you understand the importance of the visual appearance of a facility. 

S A foundation lean tool used by organizations when beginning a lean journey to develop a baseline discipline in the workplace that can then be built upon using other lean tools. It is a workplace organization methodology that engages everyone in the activities required to embrace the 5Ss sort, set in order, shine, standardize, and sustain. 

S] Papavinasam, S., Revie, R. W., Attard, M., Demoz, A., Sun, H., Donini, J. C., and Michaelian, K., "Inhibitor Selection for Internal Corrosion Control of Pipelines 1. Laboratoty Methodologies, CORROSlON/99, NACE Annual Conference 1999, Paper No. 1. 

This methodology is presently being used for a synthesis of the pseudoguaianolide confertin (5S) (Eq. 20). ... 

In 2006, we again revisited Ce" with the RCI methodology [41]. This time we were able to include some limited core-valence correlation involving the 5s and 5p subshells and the careful use of a high J excited neutral threshold to define the relative positions of... 

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