Structure and synthesis of 25-hydroxycholecalciferol-26,23-lactone, a metabolite of vitamin D3

Abstract

The four possible stereoisomers of a new metabolite of vitamin D₃, 25-hydroxycholecalciferol-26, 23-lactone, have been synthesised; we establish that the natural product has the 23R, 25S stereochemistry, and that it has 3 in bringing about intestinal calcium absorption.