Bee pheromone

An enantio-selective enzymatic hydrolysis of meso( )-2,5-diacetoxy-3-hexene gives (+)-( )-(25 ,5/ )-5-acetoxy-3-hexen-2-ol in 77% yield (92% ee).97 The monoacetate with its two allylic groups offers possibilities for stereo-controlled introduction of nucleophiles via Pd(0) catalysis. Synthesis of both enantiomers of the Carpenter bee pheromone based on this strategy is presented in Scheme 5.14.98... 

Birlirakis N., Briand L., Pernollet J.-C. and Guittet E. (2001) 1H, 13C and 15N chemical shift assignment of the honey bee pheromone carrier protein ASP1. J. Biomol. NMR 20, 183-184. 

Additional examples where chloroacetates from acyclic dienes have been used include the synthesis of pentadienylamines [96], dienesulfones [97], c-methylenecyclopentenones [98], marine natural products [99], and the carpenter bee pheromone [82]. Some additional Synthetic applications of the chloroacetoxylation of cyclic dienes are given in Refs. [100-104]. Chloroacetoxylation was also used to prepare a number of starting materials for the intramolecular reactions discussed in this chapter. 

The diacetoxylation works well with a number of cyclic and acyclic conjugated dienes and has been applied to the synthesis of natural products . For example, the meso diacetate from 2,4-hexadiene was used for the enantiodivergent synthesis of the carpenter bee pheromone. ... 

One of the four stable stereoisomers of 7-ethyl-2-methyl-l,6-dioxaspiro[4.5]decane, a bee pheromone, has been synthesized using 40 according to the route shown in Scheme 44. The IS, 5S, 7 S-isomer 328, derived from both ethyl L-lactate and malic acid (precursor for 325), is produced in good yield with an optical purity of 96% [19]. 

The reagent was used to resolve 5-cyanopentane-2-ol (1), a precursor to the four possible isomeric lactones (3). One of the cis-enantiomers is the carpenter bee pheromone. ... 

Heptan-2-one is the bee pheromone mentioned on p. 48. It has no symmetry so all its seven carbon atoms are different. The carbonyl group is easy to identify (208.8 ppm) but the rest are more difficult. The two carbon atoms next to the carbonyl group come at lowest field, while C7 is at highest field (13.9 ppm). It is important that there is the right number of signals at about the right chemical shift. If that is so, we are not worried if we cannot assign each frequency to a precise carbon atom (such as atoms 4, 5, and 6, for example). As we said before, don t be concerned with the intensities of the peaks. 

Using catalytic amounts of the morphoUne salt of a chiral phosphoric acid such as compound 241 and Hantzsch ester 242 as the hydride source. List et al. were able to achieve highly selective reductions of a broad variety of a,p-unsaturated carbonyl compounds like famesal (243) as demonstrated in the enantioselective synthesis of the bee pheromone (/ )-244 (210) (Scheme 56). Notably, this method was found to be superior when compared to the use of chiral amine-based catalysts with respect to enantioselectivity in several examples employing stericaUy unhindered aliphatic aldehydes (209). 

Scheme 56 Asymmetric counteranion-directed transfer hydrogenation in the synthesis of the bee pheromone (S)-244...

Boch, R., Shearer, D. A. and Young, J. C. (1975) Honey bee pheromones field tests of natural and artificial queen substance. J. Chem. EcoL, 1, 133-48. 

Meso diacetates obtained from 1,4-diacetoxylation of conjugated dienes have been used for enzyme-catalyzed hydrolysis in enantioselective transformations [79-85]. In an application toward the carpenter bee pheromone (Scheme 11.18) [79], the meso-diacetate 54, obtained from stereoselective 1,4-diacetoxylation of (B,Z)-2,4-hexadiene, was enzymatically hydrolyzed to hydroxyacetate 55 with 92%... 

Dicarboxylic esters are used to prepare polyesters and polyamides. The residual double bonds permit cross-linking of the polymer chains. Cross metathesis of methyl oleate with excess ethene affords methyl 9-decenoate, a key intermediate in the synthesis of queen bee substance , a honey bee pheromone. 

The dimerization of butadiene is a useful method for the synthesis of various natural products. Pellitorine, which is an insecticidal compound isolated from Amcydkm pyrethrum roots, queen substances, which are well-known honey bee pheromones, ds-dvetone, which is a naturally occurring unique symmetric 17-manbered cyclic ketone, and recifeiolide, which consists of a 12-membered lactone firamwork, can readily be synthesized from butadiene dimers. 

A further significant example is the stereospecific synthesis of (/ , 5 )-5-hydroxy-2-methylhexanoic acid lactone (the major component of the Carpenter bee pheromone) [5 c]. 

The same telomer was used by Baker et al. to synthesize the dimethyl-pentadecari 2-ol, the pheromone of the pine sawfly [16]. Also the queen substance, a well-known honey bee pheromone, is formed starting from the malonate telomer, which has exactly the right carbon number and a suitable functionality for a facile synthesis of this natural product (Equation 16) [17]. 

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