A novel method of deprotecting primary alcohols protected with either benzyl or trityl groups by using bromodimethylborane under mild reaction conditions (dichloromethane, -20 to 5°C) has been applied to the synthesis of optically pure mono-acid or mixed-acid 1,2- or 2,3-diacyl-sn-glycerols. This method was particularly useful for the synthesis of long saturated acyl (C12 to C24) as well as unsaturated diacyl-sn-glycerols since little or no acyl migration occurred during deprotection. Diacylation of 3-benzyl-sn-glycerol or 1-benzyl-sn-glycerol followed by bromodimethylborane debenzylation gave mono-acid 1,2- or 2,3-diacyl-sn-glycerols, respectively. The mixed-acid 1,2- or 2,3-diacyl-sn-glycerols were prepared from 1-acyl-sn-glycerols or 3-acyl-sn-glycerols, respectively, by tritylation, acylation with a different fatty acid, followed by detritylation with bromodimethylborane.
Bibliographical noteFunding Information:
This work was supported by National Institutes of Health research grant HL-26335 and training grant HL-07291 and with financial support from the Whitaker Health Sciences Fund.
- acyl migration
- diacyl-sn-glycerol synthesis