Three new 1α-alkyldaphnane type diterpenoids, wikstroelides R-T (1-3), together with three known analogs, genkwadane C (4), pimelea factors S6 (5) and S7 (6), two known 1α-alkyldaphnane ketal-lactone type diterpenoids, pimelotides A (7) and C (8), and a known daphnane type diterpenoid, simplexin