The first total synthesis of (-)-mucosin (6), an unusual marine hydrindane natural product incorporating a prostaglandin-like submotif, has been achieved. As a result of the campaign, three of the four all-carbon stereocenters in the purported structure 1 have been revised. Of particular note is the excellent control over β-chirality in conjugate addition to ester (-)-22 and the facial selectivity in the subsequent protonation of an intermediate silyl ketene acetal.