CAN to SPI converter
Such chips don't exist because that wouldn't make any sense. To understand why, you need to know how SPI and CAN work.

In SPI, transmission is always started by an initiative from the master. In CAN, any node can start a transmission at any time, unless the bus is busy, in which case they will queue the message and send it the next time it wins a bus arbitration. SPI does not have the concept of bus arbitration.

In SPI, there is always a slave select signal, which can be used in multiple ways to determine which node(s) that listen. In CAN, every node always listens to every message and the decision if they should act on it or not is done by firmware, or by filters set through firmware.

SPI only allows 1:n communication with a master present. Slaves cannot speak directly to each other without the master initiating the communication, although they can transfer data between each other through a daisy-chain design. CAN works without the presence of a dedicated master, any node can speak to any other node.

SPI supports completely variable baudrates and much higher ones than CAN.

CAN has standardized data link layer frames with identifiers, CRC and end-of-frame fields etc. CAN controllers handle a lot of things automatically, that you would have to implement manually in SPI.

Etcetera etcetera.



So the chip you are looking for is a project-specific microcontroller, adapted to the particular needs of a certain product, for which you have to write custom firmware. Preferably, the MCU should have a CAN controller on-board. Pretty much every MCU on the market has SPI on-board.