Abstract: An alkylative cycloaddition method is provided that is particularly useful for the synthesis of many of the Vitamin D analogues with differing side chains. Thus, a preferred synthesis is of Vitamin D analogues having a side chain R.sub.1 where a substantially geometrically pure first precursor having the structure ##STR1## and a second precursor are provided, the second precursor being a 1,7 enyne. These precursors are reacted in the presence of a palladium catalyst to form compounds having the structure ##STR2## where R.sub.2 hydrogen, hydroxyl, lower alkoxy, fluorine, or a protecting group, and R.sub.3 is hydrogen, hydroxyl, lower alkoxy, fluorine, or a protecting group.

Abstract: A process for the preparation of 1,4-dihydropyridine compounds, especially N-substituted 1,4-dihydropyridine compounds, is disclosed. The compounds are useful as cardiovascular agents and also as starting materials for the preparation of certain cyclized compounds which have properties as calcium entry blockers.

Abstract: Expansion of a ring structure and extension of a noncyclic structure containing a ketosulfone grouping in the ring by reaction with a 2-X-alkyl-3-allyl-trialkylsilane intermediate in which X is a leaving group and conversion to an expanded ring.

Abstract: Allylic alkylation with retention of configuration of a substrate having an allylic carbon-oxygen bond by reaction with a nucleophile in the presence of a Pd.degree. with an excess of a phosphine.

Abstract: A method for converting organic carboxylic acid or esters to an organic ketone with the loss of the carboxylic acid carbon atom in which the organic carboxylic acid or its ester is first subjected to a sulfenylation reaction for positioning an --SR group alpha to the carboxylic acid group and then subjecting the sulfenylated product to oxidative decarboxylation.