| 主权项 |
1. An organo catalytic process for the preparation of decanolides of Formula Ic with high enantioselectivity wherein R1 and R2 is independently selected from the group consisting of H, OH, substituted or unsubstituted (C1-C5) alkyl; () represents cis or trans position of R1 and R2 with the proviso, when R1 is methyl either in cis or trans position, R2 is —OH on the same position with regard to R1, wherein the said process comprising the steps of: i) enantioselective allylboration of aldehyde (1) in presence of allyldiisopinocamphenylborane at temperature in the range of −120° C. to −80° C. for 1-2 hours in non-polar organic solvents selected from the group consisting of diethyl ether, pentane, cyclopentane, benzene, toluene, 1,4-dioxane, chloroform, and mixtures thereof followed by treatment with NaOH and aqueous H2O2 to obtain chiral allylic alcohol (3); ii) esterification of allylic alcohol (3) with TBS protected carboxylic acid (15) in presence of EDCI HCl, DMAP in DCM at temperature range 0° to 30° C. for 5 to 8 hours with subsequent deprotection of TBS in presence of TBAF in THF for 6-8 hours yields allylic alcohol (17); and iii) ring closing metathesis reaction of compound (17) in presence of Grubbs II catalyst (5 to 15%) in dry DCM for 18-24 hours to obtain decanolides of Formula Ic. |
