A solution of the acetylene (33) (0.4 g, 1.02 mmol) in dry THF (5 ml) at room temperature under nitrogen was treated with borane-dimethyl sulphide complex (1.04 ml of a 2M solution in THF, 2.08 mmol) and the resulting solution stirred for 1 hour, after which time no starting material was present on tlc. The reaction was then treated sequentially with water (2 ml), 2N aqueous sodium hydroxide (1 ml) and 30% hydrogen peroxide (1 ml). The resulting solution was left a further 15 minutes, then ethyl acetate added and the organic layer separated. The aqueous layer was re-extracted with ethyl acetate, the organic layers combined, dried (MgSO4) and evaporated. The crude product obtained in this manner was purified on silica (5 g). Elution with 10% ethyl acetate in petrol gave tert.-butyl 22-hydroxydocosanoate (34) as a white solid (0.23 g, 54%).
