The synthetic route of pyrrovobasine ( ) is shown in Scheme 1. The key to this synthesis is the short and scalable synthesis of the vobasinol skeleton 2, a key intermediate in the biosynthetic pathway. Therefore, the use of an inexpensive and scalable reaction that can be performed on a decagram scale is critical for the large-scale synthesis of pyrrovobasine (1). Therefore, we decided to perform the C-C bond formation reaction mainly in the early stage of the synthesis. In addition, we avoided using expensive transition metals such as Pd in the C-C bond formation reaction as much as possible, especially in the early stage of the large-scale synthesis. First, D-tryptophan was used as the starting material and N-propargylated by reaction with propargyl bromide 5. The resulting compound was then reacted with α-ketoglutaric acid 6, affording the cyclized compound 7 in 49% (2 steps) (trans/cis = 2:1). Compound 7 was successfully used for the synthesis of tetracyclic compound 8 in 88% yield (40 g) via Dieckmann condensation, which proved to be very useful in the synthesis of 1,3-dicarbonyl compounds. It is worth noting that the tetracyclic compound 8 can be synthesized on a 40-gram scale from the starting material D-tryptophan in a 3-step procedure without any protecting group using inexpensive reagents. Subsequent decarboxylation of 8 followed by Boc protection led to the synthesis of 9.