highly stereoselective manner from a common intermediate from our syntheticstudies on tetrodotoxin. The key features in the synthesis were as follows: neighboringgroup participation of a trichloroacetamide to allow regioselective and stereoselective hydroxylation, protection of a delta-hydroxylactone as an ortho ester, and guanidine installation through the use of Boc-protected isothiourea. Global