Targeted protein degradation (TPD) holds immense promise for drug discovery, but mechanisms of acquired resistance to degraders remain to be fully identified. Here, we used clustered regularly interspaced short palindromic repeats (CRISPR)-suppressor scanning to identify mechanistic classes of drug resistance mutations to molecular glue degraders in GSPT1 and RBM39, neosubstrates targeted by E3 ligase substrate receptors cereblon and DCAF15, respectively. While many mutations directly alter the ternary complex heterodimerization surface, distal resistance sites were also identified. Several distal mutations in RBM39 led to modest decreases in degradation, yet can enable cell survival, underscoring how small differences in degradation can lead to resistance. Integrative analysis of resistance sites across GSPT1 and RBM39 revealed varying levels of sequence conservation and mutational constraint that control the emergence of different resistance mechanisms, highlighting that many regions co-opted by TPD are nonessential. Altogether, our study identifies common resistance mechanisms for molecular glue degraders and outlines a general approach to survey neosubstrate requirements necessary for effective degradation.

A new strategy for the functionalization of sterically hindered terminal olefins is reported. Alkenes bearing quaternary carbons at the allylic or homoallylic position are readily oxidized to the corresponding aldehydes by palladium/copper/nitrite catalysis. A broad range of functional groups including esters, nitriles, silyl ethers, vinylogous esters, ketones, lactones, and β-ketoesters are tolerated under the reaction conditions. The crude aldehyde products can be transformed further, enabling direct conversion of hindered terminal alkenes to various other synthetically useful functional groups, resulting in formal anti-Markovnikov hydroamination, among other transformations.

D 12-Prostaglandin J family is recently discovered and has potent anti-cancer activity. Concise syntheses of four D 12-prostaglandin J natural products (7-8 steps in the longest linear sequences) are reported, enabled by convergent stereoretentive cross-metathesis. Exceptional control of alkene geometry was achieved through stereoretention.

An enantioselective synthesis of 15-deoxy-Δ12,14-prostaglandin J2 is reported. The synthesis begins with the preparation of enantiopure 3-oxodicyclopentadiene by a lipase-mediated kinetic resolution. A three-component coupling followed by a retro-Diels–Alder reaction provides the C8 stereochemistry of the prostaglandin skeleton with high enantioselectivity. Stereoretentive olefin metathesis followed by a Pinnick oxidation affords 15-deoxy-Δ12,14-prostaglandin J2 in high enantiopurity.