New natural 6-deoxo brassinosteroids, 6-deoxoteasterone 1, 3-dehydro-6-deoxoteasterone 2 and 6-deoxotyphasterol 3, as well as 6-deoxocastasterone 4, are synthesized from (20S)-20-formyl-6β-methoxy-3α,5-cyclo-5α-pregnane 5.