1.7- Dioxa 5.5 undecane

Dibcnzyl-10-(2-propenyl)-9,ll-dioxa-3,6-dia7,a-10-borabic>clo[6.3.0 undecane-2,7-dione Typical Procedure33 ... 

The tartramide-based reagents, 10-allyl-3,6-dibenzyl-9,ll-dioxa-3,6-diaza-10-borabicyclo[6.3.0]-undecane-2,7-diones, are significantly more enantioselective than the parent tartrate ester derivatives7lb 73. Unfortunately, they have poor solubility at — 78 =C and consequently reactions times are long and conversions are often poor. The full scope of this tartramide reagent system awaits the development of a more soluble auxiliary. 

C NMR spectroscopy of 1,7-dioxa- (314), l-oxa-7-thia- (315), and 1,7-dithiaspiro[5.5]undecane (316) and many of their derivatives, with special emphasis on stereoelectronic and steric effects governing the configurational and conformational properties of these compounds (484-486). This work showed that chemical-shift parameters developed for six-membered carbocyclic compounds in chair conformations (149) could be applied successfully only to sulfur and not to oxygen heterocycles (486). 

Dioxa-4,6,8-trinitro-4,6,8-triaza-hendecane, or 2,10-Dioxa-4,6,8-trinitrO 4,6,8-triazo-undecane,... 

A 500-ml Erlenmeyer flask was charged withl,5-dioxa-9-aza-8,8,10,10-tetramethyl-spiro [5,5]-undecane (0.04 mole) dissolved in 150 ml of methanol and then treated with 40 ml of 35% aqueous hydrogen peroxide followed by sodium tungstate dehydrate (0.4 g). The mixture was left for 3 days at ambient temperature where after one day the color became dark orange. It was then extracted with three 50-mI portions of t-butyl methyl ether and dried with an anhydrous Na2S04. The solution was concentrated, and... 

The Step 1 reagent l,5-dioxa-9-aza-8,8,10,10-tetramethylspiro[5,5]-undecane was prepared according to the method of Murayama [1]. 

Dioxa-spiro(S.5]undecan 2,4-Dioxo- E14a/1, 717 (Keton + Malonsaure)... 

Dioxa-spiro]4.6 undecan 6-Oxo-E14a/I, 203 (Dion + Glykol)... 

Dioxa-spiro[5.5]undecan 2-Methyl- E14a/1, 251 (Keton/ Diol)... 

A set of /hc and /hh couplings has been reported by Selambarom et alP for a novel compound, [15, 25, 65, 75]-l,6-diaza-4,9-dioxa-2,7-dimethox-ycarbonylbicyclo[4.4.1]undecane obtained as an adduct of L-serine methyl ester hydrochloride with paraformaldehyde. The /hc and Vhh couplings have been measured by Walejko et al. for a series of glycosides of vitamin E. 

Dioxo-1,3-dimethyl-1,2,3,4-tetrahydro-pyriinidin und 2-Oxo-l,3-di-oxol ergeben in Aceton 4,8,10-Trioxo-9,ll-dimethyl-3,5-dioxa-9,ll-diaza-syn- und. . , -anli-tricyclo[5.4.0,02 e]undecan (je 35% d.Tb. F 169-170° bzw. 187-1880)6. 

Eine Mischung von 12 g 3-Nitro-3-(2-diathylamino-athylaminomethyl)-l,5-dioxa-spiro[5.5]undecan, 0,5 g Palladium/Kohle (5%) und 100 ml abs. Athanol wird bei einem Anfangsdruck von 4,2 bar hydriert. Nach Been-digung der Wasserstoff-Aufnahme werden Katalysator und Losungsmittel entfernt, der Riickstand in Ather auf-genommen und mit Chlorwasserstoff das Tris-hydrochlorid ausgefallt Ausbeute 9,5 g (62°/0 d.Th.) F 152-153° (aus Methanol/Ather). 

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