The reaction of a compound of the formula IVA with a compound of the formula R1CHO to produce a compound of the formula VA is typically carried out in the presence of a reducing agent such as sodium cyanoborohydride, sodium triacetoxyborohydride, sodium borohydride, hydrogen and a metal catalyst, zinc and hydrochloric acid, or formic acid at a temperature from about ???60??? C. to about 50??? C. S