The Schreiber team found that the NiCl2 and CrCl2 promoted addition of alkynyl iodide to aldehyde effectively. The reaction provides a 2:1 mixture of desired product and its isomer. However, the undesired isomer can be recycled to the desired epimer in three steps, including Swern oxidation and Corey's asymmetric reduction. Pd catalyzed partial hydrogenation of the alkyne to establish the Z-configuration at C(8)–C(9). The pivaloyloxy group was then converted to a bromide for the final coupling. A stereoselective enolate alkylation between the allylic bromide with the lithium enolate derived from the second fragment provided a 3:1 mixture of isomers and completed the backbone assembly of (-)-discodermolide. During the final conversion, the NaBH4 reduction of ketone provided a separable 2.5:1 mixture of isomers. The Schreiber synthesis of (-)-discodermolide has an overall yield of 3.2% with a longest linear sequence of 24 steps and 36 total steps. In 1996, the Schreiber group published the total synthesis of natural discodermolide with similar synthetic strategy (4.3% overall yield, 36 steps, 24 steps longest linear sequence.